Subject: Working group last call on RTP to Draft Standard

From: Stephen Casner <[email-masked]>
Date: Wed, 27 Oct 1999 23:55:16 -0700 (Pacific Daylight Time)

To the AVT Working Group:

This message announces the working group last call for comments on the
set of drafts needed to advance RTP spec to Draft Standard status.
This working group last call is to end with the AVT session at the
IETF meeting in two weeks.  At the meeting, we will propose submission
for IESG Last Call.  Assuming there are no objections, the goal will
be to make edits on site if possible to address any comments, and then
submit to the Area Directors.  We'd like to conclude this process!

In addition, this is a request to RTP implementors to fill in the
interoperability checklist that we will need to accompany the drafts
for advancement to Draft Standard.  We've made the same request
informally before, but this time we're asking that you do this in the
next two weeks so that we can have at least a first-pass tally at the
meeting.  If it looks like there are features for which we don't have
two interoperable implementations, we may have to remove those
features from the draft, or do some additional implementation and
interop testing!

Here are the details on the drafts starting WG last call:

The RTP spec and the A/V Profile have been updated to reflect the
changes agreed upon at the last meeting.  These drafts have not made
it through the Internet-Drafts queue yet, so you can get them from

    ftp://ftpeng.cisco.com/casner/outgoing/draft-ietf-avt-rtp-new-05.ps
    ftp://ftpeng.cisco.com/casner/outgoing/draft-ietf-avt-rtp-new-05.txt
    ftp://ftpeng.cisco.com/casner/outgoing/draft-ietf-avt-profile-new-07.ps
    ftp://ftpeng.cisco.com/casner/outgoing/draft-ietf-avt-profile-new-07.txt

The .ps versions have changebars relative to RFC 1889 and 1890.

The spec and profile drafts need to be accompanied by the drafts on
RTP MIME type registration and SDP bandwidth specifiers for RTCP which
are referenced (non-normatively) by the spec and profile drafts.
These drafts will be submitted for publication as Proposed Standards.

    ftp://ftpeng.cisco.com/casner/outgoing/draft-ietf-avt-rtp-mime-01.txt
    draft-ietf-avt-rtcp-bw-00.txt  (no recent edits)

RTP testing and interoperability are addressed in Informational drafts
that have also been updated and should appear shortly:

    draft-ietf-avt-rtptest-02.txt
    draft-ietf-avt-rtp-interop-02.txt

The second of these drafts is the checklist for interoperability
statements on the RTP spec.  We do need one more draft to cover the
interoperability criteria for the A/V profile, which is to be posted
shortly after the IETF meeting.
					-- Steve and Colin

---

From: Stephen Casner <[email-masked]>
Date: Thu, 28 Oct 1999 23:46:41 -0700 (Pacific Daylight Time)

I should add a followup to my working group last call for comments on
the RTP spec:

*** If you have in the past sent comments to me or the other authors
*** of the RTP spec or profile which you feel have not been
*** appropriately addressed, then PLEASE repeat them now to the
*** rem-conf list, or to me individually if you prefer, because it is
*** entirely possible that I may have overlooked something.

Of course, I won't reopen issues that we have decided, but I want to
make sure there aren't corrections or clarifications that I have
missed.

As I mentioned, the changes to the RTP spec drafts were those we
discussed at the last meeting and/or on the list.  The changes made in
draft-ietf-avt-rtp-new-05 are:

  - The pseudo-code for the collision/loop detection algorithm in
    Section 8 has been changed to pseudo-C syntax to make the if-
    then-else structure more clear.

  - As discussed at the last meeting and on the list, text was added
    about keeping packets from the new address after a SSRC collision
    of two remote sources occurs.  This is for the case of mobile
    sources that change their IP address.

  - Reverse reconsideration is also used to possibly shorten the delay
    before sending RTCP SR when transitioning from passive receiver to
    active sender mode.

  - Timing out a participant is to be based on inactivity for a
    number of RTCP report intervals calculated using the receiver RTCP
    bandwidth fraction even for active senders.

  - Added text to say that active senders use RR packets in addition
    to SR packets when they have more than 31 sources to report on.

The changes made in draft-ietf-avt-profile-new-07 are:

  - The Comfort Noise (CN) static payload type number was changed from
    19 back to 13 as it was in the -01 version from which the value
    was incorporated into other groups' specifications.

  - The RTP timestamp clock rate for G722 was changed from the actual
    sampling rate of 16000 Hz back to 8000 Hz as it was in RFC 1890.
    A note has been added to clarify this discrepancy between the
    actual sampling rate and the RTP timestamp clock rate.

  - A note was added about MPA always using RTP timestamp clock rate
    90000 regardless of the audio sampling rate.

The changes to draft-ietf-avt-rtp-mime-01.txt are:

  - The mapping between MIME parameters and fmtp was clarified.

  - A registration form for the RED payload format was added.

  - An optional parameter "type" was added to the registration form
    for MPV.
							-- Steve